The secret of London Irish's success is no secret. They are the happiest team in the country and consistently add up to far more than the sum of their varied parts. At Dublin airport early last Saturday morning the buzz of feelgood camaraderie in the departure lounge contrasted strikingly with their bleary-eyed fellow passengers. On Monday, as a reward, they went bowling instead of training. Only one other side in Europe this past decade has won away at Leinster in the tournament's opening home game; little wonder they are so cheerful.

The question now is twofold: can they sustain their gleeful momentum against the Scarlets today and will England be brave enough to follow their dynamic blueprint? Presently there are only three Exiles players – the Armitage brothers and Paul Hodgson – in the senior England squad and Delon Armitage is injured. Ask the club captain, Bob Casey, whether this is an error of judgment and he leads you away to a quiet corner of the Sunbury training ground to discuss one particular individual. "My personal opinion is that Kendo's on fire," Casey says. "I just think his time is now."

Kendo – otherwise the athletic, good-humoured Nick Kennedy – just happens to be Casey's next-door neighbour but there is more to it than natural bias. The Exiles would far prefer to keep the 28-year-old Kennedy to themselves this autumn, rather than wave him off to national service in Bagshot for a month.

It is simply Casey's professional opinion that no one in England – and possibly Europe – can touch his friend when it comes to lineout steals and airborne influence. If he were in Martin Johnson's shoes, forced to choose between Kennedy and Steve Borthwick, the current England captain, he would unhesitatingly opt for the former. "I think he and Simon Shaw would be brilliant together," Casey says bluntly. "Kendo's got to be involved with England somehow because the amount of steals he creates is amazing."

Kennedy himself is clear about his winter intentions. "I think Steve and I can play together," he says. "But I'm going to say that because he's the captain and I want to play." Another good display by the late developer today – "Friday night will mean nothing if we lose" – against a Scarlets pack that has won 47 of its last 48 lineouts will further fuel the ongoing debate.

The Leinster match, in fact, may just prove to be a seminal moment in his career. The explosive, expletive-laden public reaction to being gouged by the home flanker Shane Jennings – subsequently banned for 12 weeks – has certainly unmasked him as a more intense competitor than people sometimes give him credit for. He also destroyed Leinster's lineout.

"He put their lineout under so much pressure that, literally, the ball just fell into my arms three or four times," Casey says. "I wasn't even being lifted. Their hooker simply ended up throwing it over Kendo. He had them on the rack big-time."

With question marks over both Australia and New Zealand in that same area, it does not require a giant leap of the imagination to envisage Kennedy causing similar aerial havoc at Twickenham this autumn. As things stand, though, he sits a distant fifth in the queue, behind Borthwick, Shaw, Louis Deacon and Ben Kay.

Casey cannot understand it: "Even if you wanted him to come off the bench to change a game, he would be perfect. The argument about him not being tough enough doesn't stack up. I remember running into him as a skinny academy kid training with us for the first time. At the first ruck he came steaming in and I took offence. Fair enough, he stood up to me and unleashed a few.

"Yes, he's a very nice guy off the pitch and one of the funniest in our team in terms of banter but he has a ruthless streak to him. He's one of the most professional guys I've worked with and he's just vital to what we do at London Irish. I'm not sure he can do much more."

In fairness to the England hierarchy, Kennedy did suffer a knee injury towards the end of last season which ruled him out of the Guinness Premiership final and restricted his summer contribution at the Churchill Cup. Irish insiders say he was not fully fit but he is now. There is also the small matter of Johnson's preferred tactical approach.

"I'm unaware how England want to play," stresses Toby Booth, the Exiles' head coach. "All I can comment on is what Nick does for us. He's an exceptional lineout forward and he's worked very hard at the contact stuff they have asked him to do more of. He's even averaging a 'tackle jackal' turnover per game which, for a guy of his height is quite hard to do."

Kennedy readily acknowledges he is making up for lost time. He used to play football and basketball and had never seriously played in the second row until the age of 20 when he was studying sports science at Portsmouth University.

"I came into it fairly late and there were certain aspects of my game missing because I hadn't played mini rugby or England schools like all the other guys. It was a very steep learning curve.

"I never used to contest for the ball on the floor, for instance, because I was simply told to go to guard. It was just something I never thought of. I'm 6ft 8in tall, why bother? I didn't even start doing any weights until I was 20. As a result, I'm getting better as a rugby player all the time."

Kennedy, who went out with the actress Ali Bastian of The Bill and Strictly Come Dancing fame until recently and is learning to play the guitar, may be known as a practical joker but he is deadly serious about the winter ahead.

"Being given my first cap against the Pacific Islanders last season and then getting dropped just motivates you further. You've had a taste of it and you want it more. It makes you so hungry. You want to go out and prove people wrong.

"They're allowed to make changes to the EPS squad in January and I'm going to do everything I can to get in."